Energy storage systems have the potential to extend and optimize the operating capabilities of the grid, since power can be stored and used at a later time. This allows for flexibility in generation and distribution, improving the economic efficiency and utilization of the entire system while making the grid more reliable and robust. Additionally, alternatives to traditional power generation, including variable wind and solar energy technologies, may require back-up power storage. Thus, modernizing the power grid may require a substantial volume of electrical energy storage (EES).